The invention relates generally to photoconductive image forming, and more particularly to photoconductive image forming utilizing a one component non-magnetic toner deposited on an image forming substrate.
There are several conventional photoconductive image forming methods. One conventional method of forming an image, the Carlson process, is disclosed in U.S. Pat. No. 2,297,691. The image is formed by adhering an insulating toner in accordance with the potential of a latent image of a latent image bearing device. The Carlson process has been improved as disclosed in U.S. Pat. Nos. 3,909,258 and 4,121,931. The one component magnetic developing method has several problems. A high positioning accuracy of each part is required to obtain a clear image. In addition, a full color image is very difficult to form since the magnetic powder of the toner is difficult to color.
Two component developing methods are disclosed in U.S. Pat. Nos. 2,618,552 and 2,846,333. Although the developing electrode effect results in a clear image, two component developing methods, however, suffer from several drawbacks. First, the density of the carrier must be carefully controlled. Additionally, the image is distorted due to the scavenging effect.
Japanese Laid-Open Patent No. 114163/82 discloses a one component non-magnetic contact developing method. This method also has shortcomings. The contact developing method causes the toner adhesion to the non-image portion to degenerate, resulting in deterioration of the picture quality. Further, the toner transporting device is expensive since it serves a special function.
Accordingly it is desirable to provide for photoconductive imaging forming which does not suffer from these shortcomings of the prior art.